1 /*-
2 * Copyright (c) 2001 Dag-Erling Coïdan Smørgrav
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 * notice, this list of conditions and the following disclaimer
10 * in this position and unchanged.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 * 3. The name of the author may not be used to endorse or promote products
15 * derived from this software without specific prior written permission.
16 *
17 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
18 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
19 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
20 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
21 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
22 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
23 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
24 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 *
28 * $FreeBSD$
29 */
30
31 #ifndef _PSEUDOFS_H_INCLUDED
32 #define _PSEUDOFS_H_INCLUDED
33
34 #include <sys/jail.h>
35
36 /*
37 * Opaque structures
38 */
39 struct mntarg;
40 struct mount;
41 struct nameidata;
42 struct proc;
43 struct sbuf;
44 struct statfs;
45 struct thread;
46 struct uio;
47 struct vfsconf;
48 struct vnode;
49
50 /*
51 * Limits and constants
52 */
53 #define PFS_NAMELEN 24
54 #define PFS_FSNAMELEN 16 /* equal to MFSNAMELEN */
55 #define PFS_DELEN (8 + PFS_NAMELEN)
56
57 typedef enum {
58 pfstype_none = 0,
59 pfstype_root,
60 pfstype_dir,
61 pfstype_this,
62 pfstype_parent,
63 pfstype_file,
64 pfstype_symlink,
65 pfstype_procdir
66 } pfs_type_t;
67
68 /*
69 * Flags
70 */
71 #define PFS_RD 0x0001 /* readable */
72 #define PFS_WR 0x0002 /* writeable */
73 #define PFS_RDWR (PFS_RD|PFS_WR)
74 #define PFS_RAWRD 0x0004 /* raw reader */
75 #define PFS_RAWWR 0x0008 /* raw writer */
76 #define PFS_RAW (PFS_RAWRD|PFS_RAWWR)
77 #define PFS_PROCDEP 0x0010 /* process-dependent */
78
79 /*
80 * Data structures
81 */
82 struct pfs_info;
83 struct pfs_node;
84
85 /*
86 * Init / uninit callback
87 */
88 #define PFS_INIT_ARGS \
89 struct pfs_info *pi, struct vfsconf *vfc
90 #define PFS_INIT_ARGNAMES \
91 pi, vfc
92 #define PFS_INIT_PROTO(name) \
93 int name(PFS_INIT_ARGS);
94 typedef int (*pfs_init_t)(PFS_INIT_ARGS);
95
96 /*
97 * Filler callback
98 * Called with proc held but unlocked
99 */
100 #define PFS_FILL_ARGS \
101 struct thread *td, struct proc *p, struct pfs_node *pn, \
102 struct sbuf *sb, struct uio *uio
103 #define PFS_FILL_ARGNAMES \
104 td, p, pn, sb, uio
105 #define PFS_FILL_PROTO(name) \
106 int name(PFS_FILL_ARGS);
107 typedef int (*pfs_fill_t)(PFS_FILL_ARGS);
108
109 /*
110 * Attribute callback
111 * Called with proc locked
112 */
113 struct vattr;
114 #define PFS_ATTR_ARGS \
115 struct thread *td, struct proc *p, struct pfs_node *pn, \
116 struct vattr *vap
117 #define PFS_ATTR_ARGNAMES \
118 td, p, pn, vap
119 #define PFS_ATTR_PROTO(name) \
120 int name(PFS_ATTR_ARGS);
121 typedef int (*pfs_attr_t)(PFS_ATTR_ARGS);
122
123 /*
124 * Visibility callback
125 * Called with proc locked
126 */
127 #define PFS_VIS_ARGS \
128 struct thread *td, struct proc *p, struct pfs_node *pn
129 #define PFS_VIS_ARGNAMES \
130 td, p, pn
131 #define PFS_VIS_PROTO(name) \
132 int name(PFS_VIS_ARGS);
133 typedef int (*pfs_vis_t)(PFS_VIS_ARGS);
134
135 /*
136 * Ioctl callback
137 * Called with proc locked
138 */
139 #define PFS_IOCTL_ARGS \
140 struct thread *td, struct proc *p, struct pfs_node *pn, \
141 unsigned long cmd, void *data
142 #define PFS_IOCTL_ARGNAMES \
143 td, p, pn, cmd, data
144 #define PFS_IOCTL_PROTO(name) \
145 int name(PFS_IOCTL_ARGS);
146 typedef int (*pfs_ioctl_t)(PFS_IOCTL_ARGS);
147
148 /*
149 * Getextattr callback
150 * Called with proc locked
151 */
152 #define PFS_GETEXTATTR_ARGS \
153 struct thread *td, struct proc *p, struct pfs_node *pn, \
154 int attrnamespace, const char *name, struct uio *uio, \
155 size_t *size, struct ucred *cred
156 #define PFS_GETEXTATTR_ARGNAMES \
157 td, p, pn, attrnamespace, name, uio, size, cred
158 #define PFS_GETEXTATTR_PROTO(name) \
159 int name(PFS_GETEXTATTR_ARGS);
160 struct ucred;
161 typedef int (*pfs_getextattr_t)(PFS_GETEXTATTR_ARGS);
162
163 /*
164 * Last-close callback
165 * Called with proc locked
166 */
167 #define PFS_CLOSE_ARGS \
168 struct thread *td, struct proc *p, struct pfs_node *pn
169 #define PFS_CLOSE_ARGNAMES \
170 td, p, pn
171 #define PFS_CLOSE_PROTO(name) \
172 int name(PFS_CLOSE_ARGS);
173 typedef int (*pfs_close_t)(PFS_CLOSE_ARGS);
174
175 /*
176 * Destroy callback
177 */
178 #define PFS_DESTROY_ARGS \
179 struct pfs_node *pn
180 #define PFS_DESTROY_ARGNAMES \
181 pn
182 #define PFS_DESTROY_PROTO(name) \
183 int name(PFS_DESTROY_ARGS);
184 typedef int (*pfs_destroy_t)(PFS_DESTROY_ARGS);
185
186 /*
187 * pfs_info: describes a pseudofs instance
188 *
189 * The pi_mutex is only used to avoid using the global subr_unit lock
190 * for unrhdr. The rest of struct pfs_info is only modified during
191 * vfs_init() and vfs_uninit() of the consumer filesystem.
192 */
193 struct pfs_info {
194 char pi_name[PFS_FSNAMELEN];
195 pfs_init_t pi_init;
196 pfs_init_t pi_uninit;
197
198 /* members below this line are initialized at run time */
199 struct pfs_node *pi_root;
200 struct mtx pi_mutex;
201 struct unrhdr *pi_unrhdr;
202 };
203
204 /*
205 * pfs_node: describes a node (file or directory) within a pseudofs
206 *
207 * - Fields marked (o) are protected by the node's own mutex.
208 * - Fields marked (p) are protected by the node's parent's mutex.
209 * - Remaining fields are not protected by any lock and are assumed to be
210 * immutable once the node has been created.
211 *
212 * To prevent deadlocks, if a node's mutex is to be held at the same time
213 * as its parent's (e.g. when adding or removing nodes to a directory),
214 * the parent's mutex must always be acquired first. Unfortunately, this
215 * is not enforcable by WITNESS.
216 */
217 struct pfs_node {
218 char pn_name[PFS_NAMELEN];
219 pfs_type_t pn_type;
220 int pn_flags;
221 struct mtx pn_mutex;
222 void *pn_data; /* (o) */
223
224 pfs_fill_t pn_fill;
225 pfs_ioctl_t pn_ioctl;
226 pfs_close_t pn_close;
227 pfs_attr_t pn_attr;
228 pfs_vis_t pn_vis;
229 pfs_getextattr_t pn_getextattr;
230 pfs_destroy_t pn_destroy;
231
232 struct pfs_info *pn_info;
233 u_int32_t pn_fileno; /* (o) */
234
235 struct pfs_node *pn_parent; /* (o) */
236 struct pfs_node *pn_nodes; /* (o) */
237 struct pfs_node *pn_next; /* (p) */
238 };
239
240 /*
241 * VFS interface
242 */
243 int pfs_mount (struct pfs_info *pi, struct mount *mp);
244 int pfs_cmount (struct mntarg *ma, void *data, uint64_t flags);
245 int pfs_unmount (struct mount *mp, int mntflags);
246 int pfs_root (struct mount *mp, int flags,
247 struct vnode **vpp);
248 int pfs_statfs (struct mount *mp, struct statfs *sbp);
249 int pfs_init (struct pfs_info *pi, struct vfsconf *vfc);
250 int pfs_uninit (struct pfs_info *pi, struct vfsconf *vfc);
251
252 /*
253 * Directory structure construction and manipulation
254 */
255 struct pfs_node *pfs_create_dir (struct pfs_node *parent, const char *name,
256 pfs_attr_t attr, pfs_vis_t vis,
257 pfs_destroy_t destroy, int flags);
258 struct pfs_node *pfs_create_file(struct pfs_node *parent, const char *name,
259 pfs_fill_t fill, pfs_attr_t attr,
260 pfs_vis_t vis, pfs_destroy_t destroy,
261 int flags);
262 struct pfs_node *pfs_create_link(struct pfs_node *parent, const char *name,
263 pfs_fill_t fill, pfs_attr_t attr,
264 pfs_vis_t vis, pfs_destroy_t destroy,
265 int flags);
266 struct pfs_node *pfs_find_node (struct pfs_node *parent, const char *name);
267 void pfs_purge (struct pfs_node *pn);
268 int pfs_destroy (struct pfs_node *pn);
269
270 /*
271 * Now for some initialization magic...
272 */
273 #define PSEUDOFS(name, version, jflag) \
274 \
275 static struct pfs_info name##_info = { \
276 #name, \
277 name##_init, \
278 name##_uninit, \
279 }; \
280 \
281 static int \
282 _##name##_mount(struct mount *mp) { \
283 if (jflag && !prison_allow(curthread->td_ucred, jflag)) \
284 return (EPERM); \
285 return (pfs_mount(&name##_info, mp)); \
286 } \
287 \
288 static int \
289 _##name##_init(struct vfsconf *vfc) { \
290 return (pfs_init(&name##_info, vfc)); \
291 } \
292 \
293 static int \
294 _##name##_uninit(struct vfsconf *vfc) { \
295 return (pfs_uninit(&name##_info, vfc)); \
296 } \
297 \
298 static struct vfsops name##_vfsops = { \
299 .vfs_cmount = pfs_cmount, \
300 .vfs_init = _##name##_init, \
301 .vfs_mount = _##name##_mount, \
302 .vfs_root = pfs_root, \
303 .vfs_statfs = pfs_statfs, \
304 .vfs_uninit = _##name##_uninit, \
305 .vfs_unmount = pfs_unmount, \
306 }; \
307 VFS_SET(name##_vfsops, name, VFCF_SYNTHETIC | (jflag ? VFCF_JAIL : 0)); \
308 MODULE_VERSION(name, version); \
309 MODULE_DEPEND(name, pseudofs, 1, 1, 1);
310
311 #endif
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